The primary objective of a distributed storage model is for local storage on each individual server to act as a pool for the cluster. In this model, the virtual machine (and any data) is stored locally for better performance. Because the data is being replicated, redundancy is achieved – opening up alternate network paths and ensuring no single point of failure.
For a distributed storage model to work properly, a high-speed network is a must. I have compiled the following list of vendors based on those who have put in a lot of work to get this model running efficiently. Here are the top four I recommend looking into; each is listed along with a short description of their solution.
Atlantis is a memory based, replicated local vSAN solution. It provides very good performance, but the setup is complex.
This solution requires three minimal servers for setup. Each server has one SSD, and at least one SAS/SATA drive. It’s still in beta, but has great feedback thus far.
Nutanix created a solution where each node has two SSD and four SAS drives. In addition, this solution requires three minimal servers for setup. Each hypervisor node has a control VM that presents all local storage to the cluster, and then handles the storage replication. This solution is definitely one to watch.
Last, but not least, is the unique route taken by Microsoft with the Hyper-V replication solution. In my opinion, this is the simplest way to achieve redundancy for the following reasons:
- There is no need to create a storage pool, or server clusters.
- If there are two active Hyper-V nodes hosting different VMs, then the third can act as the replica Hyper-V node for both. Refer to Microsoft’s Distributed File System (DFS) for more information.
There are currently several vendors out there with unique solutions for distributed storage, each with their own pros and cons. No matter which of these solutions works best for you, this topic is certainly something to be watching and researching.